Oxygen Systems Introduction Flashcards
What are three major effects of altitude on the human body?
1) Hypoxia - the deprivation of adequate oxygen supply in the body
2) Decompression Illness (Altitude Sickness) - Dissolved gases form bubbles in the blood due to decrease external pressure
3) Middle Ear Imbalance - Equalization of pressure on either side of the eardrum is blocked
What are the percentage volume of gases that make up the earth’s atmosphere?
78% nitrogen
21% oxygen
1% other gases
What occurs to pressure as altitude increases?
Decreases
What does Boyle’s Law state?
If volume increases, then pressure decreases (Constant Temperature)
What does Charles Law mean?
Volume is proportional to temperature at constant pressure
What is Dalton’s Law?
Total pressure of a mixture of gases is the sum of the partial pressure of each of the gases.
What is Graham’s Law?
Gas will defuse through a membrane from high to low pressure
What is Henry’s Law?
The weight of gas in solution is proportional to the partial pressure of the gas above the liquid
What occurs in the body at a height of 63,000 feet?
All body fluids will bubble off
What is the condition of hypoxia?
Oxygen concentration in the tissues is less than normal
As the aircraft climbs, what are some hypoxia conditions that can occur?
- Air pressure and density decreasing
- Lower mass of oxygen taken into the lungs
- Less oxygen spread over alveoli membranes into bloodstream
What is the risk of rapid rates of ascent?
Higher altitudes can be reached, leading to unconsciousness before the onset of any of the systems of hypoxia manifest.
What are some symptoms of hypoxia?
- Giddiness
- Clumsiness
- Difficulty concentrating
- Faulty Judgement
What is time of useful consciousness at 18,000 feet?
30 mins
What is time of useful consciousness at 25,000 ft?
3 mins
What is time of useful consciousness at 40,000 ft?
15 seconds
What is a pressure loss called that occurs within seconds?
Rapid Decompression
What is a pressure loss called that occurs within milliseconds?
Explosive Decompression
What are four distinct forms of decompression illness?
1. Bends (joint problems) 2 Creeps (skin manifestations) 3. Chokes (Respiratory functions) 4. Staggers (Nervous system effects)
What is middle ear imbalance?
When equalization of pressure on either side of the eardrum is blocked by a cold or similar infection
What health issues can cause middle ear imbalance?
- Common cold
- Hay fever
- Sinusitis
- Tonsilitis
How can blocked ears be cleared?
- Holding your nose and blowing hard
- Chewing
- Swallowing
- Yawning
Does middle ear imbalance occur on ascent or descent?
Descent
What are three things an oxygen system should provide?
- Storage
- Distribution
- Regulation of Oxygen
What are three types of Oxygen systems?
- Gas at high pressure
- Liquid at low temperature (LOX)
- OBOGS that used Molecular Sieve Oxygen Concentrators (MSOCs)
What is a Continuous Flow Oxygen System and what are they typically used for?
- Deliver pure oxygen to the mask continuously
- Oxygen which is not inhaled is vented along with exhaled breath
- Used for Emergency Oxygen Supply systems due to the short endurance
How do Demand-Flow Oxygen Regulators work?
- With regular set to NORMAL OXYGEN, regulator holds back the flow of oxygen until the user inhales
- Pure oxygen is diluted with cabin air each time a breath is drawn.
- Amount of dilution depends on the cabin altitude
On a Demand-Flow Oxygen Regulator system, how is 100 percent oxygen selector?
- User can select 100 percent oxygen delivery at any time by turning switch to 100% oxygen.
- Emergency switch also delivers 100% oxygen but in a continuous flow as the demand function is bypassed.
For what situations is a supply of emergency oxygen available to each crew member?
- If the main supply fails (operated manually)
- In the event of ejection or bail out (operated automatically)
Where are emergency oxygen systems usually attached?
Bottom of the seat
What occurs to the body when an airplane decompresses?
- Cabin air escapes
- Lower pressure on the body causes the pilot to suddenly exhale
- Lungs contain less oxygen
At what altitude does the human body require supplemental oxygen above? What about oxygen under pressure?
- 10000 feet
- 30 000 feet
In a liquid oxygen system, how is the oxygen supply stored ?
- Very high pressure
- Low Temperature
Wat is the primary protection against hypoxia in a passenger aircraft?
Cabin Pressurization
What are some advantages of the LOX system?
Same supply in half the weight/volume as a gaseous storage system
OBOGS produces a gas that consists of approx 95% oxygen and 5% of what other gas?
Argon
